Switch contact device



Feb. 21, 1950 F. H. COLE SWITCH CONTACT DEVICE 2 Sheets-Sheet 1 Filed Sept. 23, 1946 //VVEN7'0, F250 H. 601.5

7%W 3mm F. H. COLE SWITCH CONTACT DEVICE 2 Sheets-Sheet 2 med Sept. '23. 1946 scale of part Patented Feb. 21, 1950 UNITED STATES PATENT OFFICE g,498,25 SWITCH CONTACT DEVICE H. Cole, Los Angeles, Calif. Application September 23, 1946, Serial No. 698,791 7 Claims. (01. 200 166) 1 This inveniiei re ates t e t i Switches, more particularly to switches'of the blade type and to the contact-portions of such switches'.

An object of the presentinvention isto provide a switch contact device which is economical to manufacture, readily and inexpensively assembled, and which furnishes ainore efiicient contact between its several current carrying and engaging parts.

Affurther objectoithe invention isto retain the high conductivity advantages inherent in the use of silver switch contact elements. Iwhile'lmaterially dispensing with their high -ec')st"disady g V Another object of the invention is to provide a switch contact having a yeryshort current carrying path .and a high degree of conductivity.

Yet another object of the invention is to provide a switch contact assembly which is selfaligning, thus insuring more efficient contact between the several switch ar t s'. Still a further object of the invention is-to provide a switch assembly in wh ichthe contact force between the relatively movable [and stationary switch parts is increased automatically in accordance with increase. in the current passn hr th sw ch- The invention is egre nplified in the following des i and ill t ated by war of e am le in th compan in QWWF ESQ i which:

Fig. 1 is a side elevation of a blade type vof switch embodying the invention.

Fig. 2 is a t'opplan view of the switch disclosed i figl Fig. 3 is a longitudinal section on an enlarged of the switch mechanism shown "in Figs l d 2. a

Fig. 4 is a cross-section of the switch taken along the line 4-4 in Fig.3.

Fig. 5'is a cross-section taken along the line 5-5 inF'igVB; and h Fig. 6 -is a cross-section through a modified form of switch contact.

As shown in the drawings, the-switch consists of relatively fixed and movable .contacts 1.0, II I, suitably supported upon a main base 12. The

fixed contacts H .aresecured .to aconductive termovable portion of the switchconsists of ablade,

termed of two spaced apart arms i5, i5- suitably moun-ted on a {stud l 6. .o arried by a conductive terminal pad or base :l-l suitably secured to van porting channel or contact bracket member I9 suitably secured to the terminal l3, as by a bolt tfl extending throughbracket and terminal holes 2 22. Contact and conductorswitch elements 23, 23 are disposed on op'p ositesides' of the bracket l9 for engagement with the latter and with the switch blade 15, [5f Since these e1e- .ments'are duplicates of one'another, a descripsecured to the shoe 24'withithe inner exposed race 21 of itshead '25 provided withf'a coating 6f silver swedged or otherwise deposited thereon.

Another lower high'conductivity copper rivet 2,9 is secured toth'e lower portion of the shoeand has .fa"silvered inner face {3.0 engageable with? silvered'out'er surface 31' ,of'the copper'channel. whose lower base suriace 32 may also be silver coated. 25

The. opposed U -shaped shoe contacts and conductors" 24 are arranged on opposite sides of the channel suppor in member It}, with their .respeetiye silvered'cqpper rivets 29 engaging its side'faces SL 31. These shoes 8 1c urged toward one another by spring devices, consisting of ;a helical spring 33 having one end bearing directly or indirectly against the'eentral Ipor'tion gda of the main shoe, and its other end against 'a U -shaped spring retainer 34 engaging the head 35 of .ascrew 38 extending inwardly through the main sneeze and channel web l fia into threaded reception within a tubular spacer 31 extending between the channel webs i911, l9a.

The spring retainers .34, screws 36 and spacer tube}? servesasrelatively fined .abutments for the springs .33; as well as .sunports vfor .the main contact lshoes 24,..al1owing the spring force to he exertedi'lagainst the shoes and rge them inwardly toward one another." ,Suitably spaced locating pins 38, tamayalsoextend throiightlie channel island main conductorsfl. for I guiding the {conductors 24 and their contacts12B, ,2 9' [in their movement toward one another" andl for 1 facilitating "assembly of the device.

The contact arms l5, 15 of the switch blade are held in spaced relation by studs or bolts .39 extending through intermediate .tubularfspacers lid. Ehe blade L 1 5 isadapted to be swung from a l-emana on t a close rosi c e ee h ma coctact "24 2a ji l-cl sedrgs iiflnthe blade arms l5, l5 engage the upper ends I91: of the channel webs l9a which serve as stops limiting the extent of inward movement of the blade within the relatively fixed switch contacts 24. The faces l5a of the movable arms are also preferably silvered to provide an efficient contact and current carrying path between them and the silvered faces 21 of the upper rivets 26.

When the blade is in closed position, current may flow from it onto and through the silvered rivets 26, thence through the main conductor shoes 24 into the lower rivets 29, passing through the silver rivet and channel coating 36, 3| into the supporting member 19 from which it flows through the silver base coating 32 onto the terminal pad l3.

Contact between the various parts is maintained by the springs 33 pressing the conductor shoes 24 towards one another and the rivets 26, 29 into firm engagement with the arms l5, 15 of the blade and the outer faces 3| of the channel l9. Although not indispensable, if desired, laminations 4| of copper shim stock of generally U- shape may be disposed in engagement with the central portion 24a of each shoe with their bases 42 clamped between the base portion of the channel l9 and terminal pad [3. These layers 4! of high conductivity copper are firmly clamped to the main conductors 24 by the upper copper rivets 26 whose outer head portions engage respective brass cover plates 44 bearing against the outer lamination, and through the lower portions of which the screws 36 extend.

The shim stock 4| serves as a shunt, conveying some of the current between the upper silvered copper rivets 26 and the terminal pad l3. In addition, and because of its particular shape, it adds its spring force to that exerted by the helical springs 33 in urging the movable main contact elements 24 and rivets 26, 29 toward one another into firm contact with the silvered surfaces l5a, 3| of the blade arms and channel webs. It is to be understood, however, that the switch contact device may be used without the copper shim stock 4| and brass cover plates 44, in which form it is represented in Fig. 6.

By virtue of the arrangement described, effec tive contact is made between the various parts of the switch device. The main conductors 24 and the silvered copper rivets 26, 29 secured to them are self-aligning in view of their ability to move on the assembly screws 36 and locating pins 38, adjusting themselves automatically to any irregularities or distortions that might exist in the blade I5 and channel l9. This self-aligning feature and the ability of the shoes and rivets to move toward one another, provides an arrangement in which the contact force between the rivets 26, 29 and the blade l5 and channel I9 is increased automatically upon increase in current flowing through the apparatus. The flow of current provides a magnetic force attracting the main contacts 24 toward one another, supplementing the force of the springs 36 urging them against the blade l5 and channel [9. This is of particular advantage in heavy current applications wherein the effectiveness of the contacts is automatically enhanced and insures eiiicient transmission of the current between the blade l5 through the contacts 26, 24, 29, I9, to the terminal pad or base l3.

The switch contact device heretofore described is relatively economical to manufacture since it can be made from punched and formed parts from relatively inexpensive materials, such as high conductivity copper and brass, the only precious metals employed being the small amount of silver deposited on the contact faces of the rivets 26, 29 arms l5 and channel l9. The opposed parts are duplicates of one another, which further lends to reduction in the cost of manufacture of the switch device.

The switch device provides all of the advantages of silver contact elements, while retaining the relatively low cost advantage of copper, which is an efficient conductor of electricity between the silver contact points. The current carrying path through the switch is extremely short, with losses maintained at a minimum, since the device closely approaches the efficiency of a silver switch.

The switch contact units ll may be arranged on the terminal pad I3 in any number for engagement with the switch blades l5, depending upon the current carrying capacity of the switch, Two switch contacts are disclosed in the drawings arranged side by side, and this number may be increased, depending upon the length of the terminal pad, simply by bolting additional units 1 I to the latter member.

When the blade 15 is in closed position between the switch contacts 24, 24 and in engagement with the upper ends [9b of the channel webs, it may be held in such closed position by a latch device mounted on one of the switch contact assembly members II. This device consists of a latch 45 pivoted on the tubular spacer 31 and having an upstanding head 46 provided with a tapered face 41 and a nose 48 adapted to extend over a latch pin 49 secured to and between the arms l5, l5 of the blade, when the latter engages the channel webs I911. The blade 15, in moving to closed position, engages the tapered face 41 and forces the latch 45 from the path of the pin 49 until the blade 15 has been fully closed, whereupon the pin 49 is positioned below the nose 46, permitting the latch 45 to be returned to its locked position with its nose 48 disposed over the pin 49. This is accomplished by one or more suitable coil springs 50 encompassing the tubular spacer 31, one end 5i of each spring bearing against the locating pin 38 and its other end 52 against a latch 53, tending to swing the head 46 and its nose 48 over the latch pin 49. When in closed position, the blade cannot be elevated unless the latch nose 48 is first removed from above the pin 49.

Release of the latch 45 is accomplished by mounting a releasing lever 54 on a pivot pin 55 extending between the blade arms l5, [5. This lever has an operating arm 56 extending outwardly of the blade I 5 on one side of its pivot 55 and a latch releasing finger 51 extending inwardly of the blade on the other side of its pivot pin 55. The finger 5! is engageable with the tapered face 41 of the latch upon upward movement of the arm 56 to swing the latch nose 48 from engagement with the latch pin 49, permitting the switch to be opened by removal of the blade [5 from contact with the upper rivets 26 and shoes 24.

The latch arrangement not only holds the blade l5 in place and obtains release of the latter upon removal of the latch head 46 from the latch pin 49, but also provides a mechanical advantage means assisting in the breaking of the contact between the arms l5 and rivets 26. The lever finger 51 acts on the tapered face 41 of the latch head 46 to swing its nose 48 clear of th blade pin 46 until the latch-112953 engages the base of the channel support IS. The latch 45*actsas a fixed abutment, the point ofengagement between the finger 5T and tapered face 47 serving as a fulcrum for thereleasing lever 5'4 whose upward movement then acts on itstpivot pin" 5'5 to urge the'blade i '5" upwardly to open position. The force applied to the pivot: pin 55 fixed. to the blade 15 is greaterth'an thefor'ce applied to the lever arm 5!; since the distance between the end of the releasing arm 55 and the fulcrum point of engagement between the finger 5i and latch face 41 is much greater than the" distance between the pivot pin 55" and such' fulcrum pointiof engagement. Thus; the latch and lever arrangement 45, 54 has a two-fold purpose; it provides a releasable lock to hold the switch blade 15 in closed position, preventing inadvertent opening of the switch, and it also facilitates opening of the switch when desired.

While I have shown the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An electric switch device, including a supporting member, opposed conductors on opposite sides of said supporting member, a, generally U- shaped laminated structure having a base portion engaging said supporting member and opposed arms engaging the exteriors of said opposed conductors, a high conductivity pin extending through and securing a laminated arm to each conductor and having a silver coating on its inner end, a second high conductivity pin secured to each conductor and having a silver coating engageable with said supporting memher, and means for urging said conductors toward each other.

2. A switch contact device of the character described comprising: a base, a pair of spaced upright fixed contact members mounted on the base and having their upper edges in the same plane, said upper edges being adapted to receive the lower edges of a pair of spaced, parallel -movable switch blades and to serve as stop members therefor, a pair of upright U-shaped conductors each having a base portion and side por tions and mounted on opposite sides of the fixed contact members to make contact between their base portions and the fixed contact members and blades, and a spring for each conductor member mounted between the side portions thereof for urging its base portion inwardly independently of the other spring member.

3. A switch contact device of the character described comprising: a base, a pair of spaced upright fixed contact members mounted on the base and having their upper edges in the same plane, said upper edges being adapted to receive the lower edges of a pair of spaced, parallel movable switch blades and to serve as. stop members therefor, a pair of upright U-shaped conductors each having a base portion and side portions and mounted on opposite sides of the fixed contact members to make contact between their base portions and the fixed contact members and blades, and a spring for each conductor member mounted between the side portions thereof for urging its base portion inwardly independently of the other spring member, and a pair of contact buttons fixed to the base portion of each con-- 6 ductor member and" having'a silvered. rounded head making contact with the adjacent-fixed contact member and blade.

4. A switch contact device of thecharacter described comprising: a base; a pair of spaced, upright fixed contact members mounted on. the base and having their upper-edges in the same plane, said. upper edges being adapted to receive the lower edges of a pair of spaced, parallel movableswitch blades and to serve as stop members therefor; a threaded spacer member fixed to and extending between said fixed contact members; repair of U-shaped conductors each having a base portion and spaced side portions; a screw having a head for each conductor, extending therethrough and in threaded engagement at its inner end with said spacer member, and serving to mount its conductor on said fixed contact member with the base portion of the conductor incontact therewith and with the adjacent blade; and a spring carried by said screw compressed between the head thereof and said base portion to press the latter inwardly.

5. A switch of the character described comprising a movable contact element and a fixed contact element; said movable element comprising a pair of parallel spaced blades; said, fixed element comprising: a base; a U-shaped contact member having a base portion and spaced upright legs mounted on said base with its base portion in contact with and supported by the base; a threaded tubular spacer fixed to and extending between said legs, said legs being formed with passages in registry with the tubular spacer; a pair of U-shaped conductors each having a base portion and spaced side portions; a screw having a head for each conductor and extending through the base portion of its conductor and in threaded engagement with said spacer to mount the condoctor with its base portion in contact with a leg of the contact member and with a switch blade; and a spring for each screw compressed between the head of the screw and said base portion to urge the latter inwardly into contact with the contact member and a blade.

6. In a switch comprising a movable contact member and a fixed contact member, means for establishing electrical contact between said members comprising a pair of opposing U-shaped conductors each having a base portion and spaced side portions and mounted with the base portion in contact with opposite sides of said fixed contact member, and in contact with the movable contact member, and a spring element for each conductor located between the side portions thereof to urge the base portion of each conductor toward the opposing conductor.

7. In a switch comprising a movable contact member and a fixed contact member, means for establishing electrical contact between said members comprising a pair of opposing U-shaped conductors each having a base portion and spaced side portions andmounted with the base portion in contact with opposite sides of said fixed contact member and in contact with the movable contact member, and a spring element for each conductor located between the side portions thereof to urge the base portion of each conductor toward the opposing conductor, a contact button extending through the base portion of each said U-shaped conductor and having a silver-coated head in contact with said movable contact member, and a second contact button extending through said base portion and having a silver-coated head in contact with said fixed Number Name Date contact member. 1,966,234 Cox et a1 July 10, 1934 FRED H. COLE. 1,978,246 Bauerschmldt Oct. 23, 1934 2,193,008 Puerner Mar. 12, 1940 REFERENCES CITED 5 2,193,238 Ramsey Mar. 12, 1940 v 2,221,607 Samzelius Nov. 12, 1940 g ifixi igfi are of record m the 2,226,385 Ramsey Dec. 24, 1940 2,385,304 Schymik Sept. 18, 1945 UNITED STATES PATENTS FOREIGN PATENTS Number Name Date 10 771,239 Gale, Sr Oct. 4, 1904 Number Country Date 1,381,320 Mahoney et a1. June 14, 1921 388,509 Great Britain Mar. 2, 1933 1,465,451 Martens Aug. 21, 1923 394,200 Great Britain June 22, 1933 1,831,843 Cornfield Nov. 17, 1931 604,212 Germany Oct. 16, 1934 

